Hi Ulrich,

Thanks for the prompt response, I really appreciate it.

I unfortunately require the proprietary nvidia driver as this system, a GPU processing host, runs a few pieces of CUDA software. My other requirement is the ability to render WebGL content in Firefox for use with one of the tools.

The yum history is there - what I should have said is that I do not understand which packages might be involved. There was a kernel update after which I had to reinstall the NVIDIA drivers (from the .run file). After doing so, I found I could not render WebGL in Firefox (running in an X2Go MATE desktop session). I found that my x2go sessions were using the OpenGL Mesa GLX Indirect renderer, as reported by glxinfo, and believed that to be the cause of the WebGL problem since it requires direct rendering and a newer version of OpenGL than the Mesa GLX Indirect renderer supports. This caused me to believe I needed to render OpenGL with the nvidia driver.

I switched to the ELRepo kmod-nvidia package which produced the x2goagent errors, likely because Xorg was running with the nvidia driver. That's when I made my original post.

I've subsequently replaced the ELRepo driver with the NVIDIA driver from the .run file again. Now the GPUs are accessible and I can connect to X2Go but WebGL still doesn't function. Xorg is running with the nouveau driver according to Xorg.0.log and glxinfo reports "direct rendering: No". The Firefox about:support page shows errors like:

WebGL creation failed:
* Refused to create native OpenGL context because of blacklist entry: FEATURE_FAILURE_OPENGL_1
* Exhausted GL driver options.

Running "__GLX_VENDOR_LIBRARY_NAME=mesa LIBGL_ALWAYS_SOFTWARE=1 firefox" didn't get WebGL working, either, but did change the about:support output:

WebGL creation failed:
* Refused to create native OpenGL context because of blacklist entry: FEATURE_FAILURE_GLXTEST_FAILED
* Exhausted GL driver options.

Any idea how I can get WebGL rendered in an X2Go session again? I would assume that there wasn't a solution using X2Go if I hadn't used it successfully myself mere days ago. I intend not to use VNC if at all possible.

On Tue, Oct 19, 2021 at 2:27 PM Ulrich Sibiller <uli42@gmx.de> wrote:

Well, yum history shows you the list of updated packages.

However, nxagent should not come into touch with the nvidia stuff as
it is not using the GPU of your server. So I guess some software
inside your mate session is using OpenGL and trying to achieve that
via nvidia's libGL.
I suggest to try uninstalling the nvidia driver and see if that works.
Alternative you may reinstall mesa.

Generally you need to use software rendering. There's a workaround how
to achieve that for single applications on the x2go wiki. It might get
complicated to use that already for the session startup.

Thinking about it leads to this simple test: start an x2go session
with xterm instead of xclock. in that xterm start glxgears and see if
the session crashes. If you, try another xterm session and run

__GLX_VENDOR_LIBRARY_NAME=mesa LIBGL_ALWAYS_SOFTWARE=1 glxgears.

Uli